old dead wood from a tree stronger than any other wood from that tree?

This is a question following from several observations of a elm tree.
There was an elm tree that was wind damaged and the limbs finally came

down after several years hanging in the tree. It was old and dry but
very strong and much harder to break than a green limb.
So I am wondering what is the preparation for the strongest wood from a
given tree. Whether the weakest wood is the green alive wood. Whether
cut wood that is dried in a dryer is stronger than green wood. And
finally whether the strongest wood of all is to kill the entire tree and
let it dry for several years and then harvest the wood.
If true, what is the explanation?
Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom where dots
of the electron-dot-cloud are galaxies

Explanations I don't have, but it's well known that locust wood
(commonly known as "ironwood") can be fairly easily cut when green, but
is some of the toughest wood in the world after curing. If you have a
locust tree come down in your yard, you'd be wise to cut it up
immediately. After as little as a few weeks it may be hard enough to
wear out a chain saw. You can hurt yourself, even break a bone, trying
to cut cured locust limbs with a sharp axe (just bounces off). Locust
fence posts commonly last MUCH longer in the ground than will pressure
treated pine or fir. Greatly preferred by farmers, but they ALWAYS cut
the wood while it's green. Otherwise, it's for the landfill.
Mark 'Sporky' Stapleton
Watermark Design, LLC
www.h2omarkdesign.com
Archimedes Plutonium wrote:

Dry wood is stronger than green wood. Go look it up in the
authoritative Wood Handbook, which you can find online chapter by
chapter as free downloadable .pdf files.
See chapter 4 on mechanical properties.
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf
See Table 4-11a on page 4-28 showing the difference between green wood
and dry (~12% moisture) wood. Read the rest of the book for
explanations.
Pittsburgh Pete

The strongest tissue is always the sclerenchyma, those cells of the tree
whose purpose is to strengthen and stabilize. Technically, sclerenchyma
cells are 'dead', in that moisture has migrated from the cell leaving only
the lignan (hence, 'lignification') behind.
Dave

Thanks for the information. I will keep it in my notes file, who knows it may
come useful in future.
Say, you would not know whether animal bodies have a cell which produces the
strongest and stabilizing form that is the analogy to sclerenchyma???
Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom where dots
of the electron-dot-cloud are galaxies

Log in

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.